The present invention is related to test systems and methods, and more particularly to a system and method for testing the reaction of rare earth ions in which a transparent crystalline solid is doped to respond to radiative light energy with which the ions are excited. It is known that the reactions of such excited ions is to decay from the excited state. The decay may be radiative, in which case the reaction is the radiation of light, or the reaction may be nonradiative, in which case the reaction is in the nature of phonons. The study of the radiative reactions is not too difficult since the light output may be studied and its frequency ascertained. Nevertheless, the study of the phonon output, which is in the nature of a vibratory elastic energy is difficult to study because it may not be directly observed.